Spring Allergies

At this time of year spring allergies are rampant. New South Wales had the highest pollen counts on record. In other states it doesn't seem quite as bad but they still see a lot of people with sneezes, runny noses and red eyes.

Transcript

Norman Swan: Welcome to the program. I hope you can stay for a while because today on The Health Report, spring allergies: all you need to know and maybe even more than you wanted to; plus you'll find out about the wellbeing induced by the four-hour day and the 90-minute night in some people; how changing a day from 24-hours to four can cure quite a disabling condition.

In New South Wales at least, they're experiencing the highest pollen counts on record. It's creating a mini epidemic of hayfever and eye allergies. The story's mixed in other States, which are nonetheless still seeing their usual swag of sneezes, runny noses and red eyes.

One of the people who's been monitoring the pollen counts in New South Wales is Dr Connie Katelaris, a clinical immunologist and allergist at Westmead Hospital.

Connie Katelaris: Well this season is either terrific or terrible, depending on -

Norman Swan: - whether you're selling drugs or not I imagine!

Connie Katelaris: Depending on whether you're a patient or a doctor I suppose. It's the worst pollen season we've monitored, and we've been doing pollen counts now in the region for five years. A reasonably heavy pollen count would be in the order of 200-400 grains per cubic metre. This year we're already seeing counts in the thousands.

Norman Swan: And what is this pollen, is it wheat from the country, is it trees, what is it?

Connie Katelaris: Well any flowering plant produces pollen, as you know, it's the sexual reproductive part of the plant, so a flowering plant will produce pollen. There are certain plants, and they're the ones that have much greater pollen load, and the ones that are wind borne, are wind pollinated, because they need a much greater load of pollen to ensure continuation of the species. So grasses are by far our most prevalent. Many of the trees, particularly the European trees, the introduced deciduous trees, also are prolific pollen producers, but they have a very limited season of a few weeks only. Here in Sydney, the grass pollen season goes anywhere from September into January or February, depending on the weather.

Norman Swan: Is it a bad season everywhere in Australia at the moment?

Connie Katelaris: I'm not quite sure, because pollen counts aren't routinely done in other parts. But because we had such an amazing amount of winter rain and good weather in the spring, we would predict it would be a bad pollen season. And any other region that's had that sort of weather pattern would probably experience the same pattern.

Norman Swan: So the climate over winter is the reason why we've got a bad pollen season.

Connie Katelaris: A very important determinant, yes.

Norman Swan: So how's that manifesting in terms of individuals?

Connie Katelaris: It's manifesting with the worst hay fever many people have experienced for years, and what's interesting is a lot of people who usually don't have problems, are presenting to their doctors and their pharmacists with hay fever. These people are the people that have less a sensitisation and yet with the huge load they're actually expressing symptoms.

Norman Swan: It's overwhelming and it's taken them over the edge.

Connie Katelaris: Yes.

Norman Swan: And is it bad for asthma too?

Connie Katelaris: If you are a pollen sensitive asthmatic and it is one of your triggers, yes, those people will experience increasing asthma. The interesting thing that people have both, the rhinitis or hay fever and asthma, the very very worsening of the rhinitis will also trigger the asthma.

Norman Swan: Now hay fever, just to be clear, people think this is runny nose, sneezing, but in fact it's more than that, isn't it?

Connie Katelaris: Yes, that's what the term is typically used for. We call this seasonal allergic rhinitis, but it's an allergic reaction confined to the upper respiratory tract, and that usually, but not always, involves the eyes as well. So yes, in its milder forms, it's a bit of sneezing and running, but this can become extremely irritating and distressing. Those can block up, you can get a secondary sinusitis, you can't breathe at night, the constant running of the nose just drives people mad, and they can get secondary headaches and fatigue associated with it. So it can be quite debilitating and some people need to take time off in fact because of the symptoms.

Norman Swan: Now the ocular allergy, the eye allergy part of this is under-recognised isn't it?

Connie Katelaris: Yes certainly, particularly when people focus on the nose. All the advertisements we see focus on drying up the nose. With the seasonal allergic rhinitis, or hay fever, that is the symptoms caused by the pollens, eye symptoms are very frequent and very common and they too are very distressing. You can just imagine when you get a little bit of dust or grit in your eye how upsetting that is. If you walked around all day with that sensation, with the eyes dripping, the eyes look red, people make comments to you, so it's a very distressing part of the symptoms.

Norman Swan: We'll to come back to hay fever in a moment. There are other forms of allergic conjunctivitis, aren't there?

Connie Katelaris: Yes, the next most common is that associated with what we call perennial allergic rhinitis, those people who have symptoms all year round from things such as dust mite. There are a couple of rarer versions which are very severe diseases of the conjunctiva because they can be sight-threatening.

Norman Swan: The conjunctiva being the outside lining of the eye, the surface of the eye.

Connie Katelaris: Yes, correct. And part of the pathology there can also involve the cornea which is very essential for vision. So if you get inflammation through an allergic reaction and then scarring, then there can be problems with your sight.

Norman Swan: Let's go back to the hay fever situation, and knowing the pollens that are coming in, are you a believer in immunotherapy, allergic desensitisation, the course of injections that people can have?

Connie Katelaris: There's no doubt that there's excellent scientific evidence now that suggests that immunotherapy is highly effective when the individual has been properly chosen, where they have the right allergic sensitivity, and you have the right pollen or protein extract in your immunotherapy bottle.

Norman Swan: Let me get this right: so the right person is the person who's been found to have one specific allergen, that there's a certain form of rye grass for example, that you come positive to, and you've got an injection for rye grass that you know is pure, and you give them that, and that works quite well. But if they come up against a whole battery of allergies, it doesn't work that well, is that right?

Connie Katelaris: Yes, that's it precisely. To summarise it: if you are able to identify the right allergen and you have a good quality extract, then that person is likely to get excellent benefit from immunotherapy. It has to be done cautiously because what you're doing is injecting that person with the very protein they're allergic to, and so you do risk a more severe allergic reaction if it is not done carefully.

Norman Swan: So how do you choose the right person to do the injection so that it's done in a safe situation, and they're going to choose the right extract, because there's a lot on the market, there's a lot of people doing it.

Connie Katelaris: Absolutely. The person needs to have the right set of symptoms, they need to be skin tested or allergy tested in some way so that you can determine what proteins are stimulating the allergy, and then the pattern, from the patient's story, has to be right. For instance, if this person's come up to rye grass pollen and their symptoms are worse in March, April, May, you know that it's not the rye grass.

Norman Swan: Because rye grass is this time of the year.

Connie Katelaris: Absolutely, yes. So the history that the patient gives, the pattern of symptoms and the skin test positivity of the three things we take into consideration.

Norman Swan: And what is the risk of what they call an anaphylactic reaction, a severe allergic reaction?

Connie Katelaris: It's very, very small, we shouldn't overstate it, yet people who are undergoing this form of therapy have to understand that that is the ultimate risk, and the doctor administering the injection has to understand that that's the risk.

Norman Swan: So there's got to be full resuscitation facilities?

Connie Katelaris: Absolutely, and a proper observation period. Specialists vary in their advice regarding that, but somewhere between 30 and 45 minutes is the usual recommendation.

Norman Swan: And how long does a course last these days?

Connie Katelaris: We know that the longer you have immunotherapy for, the longer-lasting is the benefit. We usually suggest to people that they have it between three and five years.

Norman Swan: Continuously, for three or five years?

Connie Katelaris: It's not quite as bad as it sounds. It starts off as a weekly injection for the first few weeks.

Norman Swan: And then you have top-ups?

Connie Katelaris: And then you have fortnightly injections, and then it spaces out to just a monthly booster.

Norman Swan: Now what about the hay fever itself? There's a lot being advertised in the medical journals about these new non-sedating antihistamines. When I was a kid and I had terrible hay fever, you used to not want to take the antihistamines, because they used to knock you out.

Connie Katelaris: Look they are a very real advance. We've had them now for over a decade, and they certainly are useful precisely for the reasons you've outlined. They're effective in blocking the histamine response that you get with an allergic reaction, and yet they don't put you to sleep. So you can work and function and drive, drink alcohol if you must, without any risks like we had with the older agent.

Norman Swan: And I should explain here, what's going on in the lining of the hose and the eyes, is these little cells called mast cells are bursting, releasing this chemical called histamine, which then produces all this inflammation and irritation.

Connie Katelaris: Exactly. If you're an allergic person, what it means is that you're genetically predisposed to making an antibody response to a protein in your environment that most people ignore. For instance the rye grasses that we're talking about seasonal problems, when that rye grass pollen hits the lining of your nose, it then combines with that specific antibody which we call IgE which is embedded into the membrane of the mast cell, and that then triggers a very complex chemical reaction which causes the mast cell to burst and release histamine, but many other chemicals as well.

Norman Swan: So the antihistamine blocks it. How effective are these antihistamines at stopping the symptoms of hay fever?

Connie Katelaris: Well because histamine is only one of the many chemicals released from the mast cell, the antihistamine is partially effective. It is never up 100% because there are other chemicals driving the allergic inflammation as well. So antihistamines are useful for milder symptoms, for intermittent symptoms. However is somebody's got continual problems, say for instance this year, with this very long pollen season, people with pollen allergy can expect to have symptoms for four, five months of the year. They certainly need to step up to a better type of treatment.

Norman Swan: What, perhaps immunotherapy, or is it too late for immunotherapy?

Connie Katelaris: Too late for this season, so these people need to use one of the preventative agents we have, and the best we have for the nasal allergy are the intra-nasal steroids.

Norman Swan: The chemical name is beclomethasone, or budesonide.

Connie Katelaris: Budesonide and beclomethasone are two of the chemicals and these come in a nasal spray.

Norman Swan: These are the same steroids that some people take for their asthma, except you squirt them up your nose.

Connie Katelaris: Absolutely identical idea as well, that it's a preventer, you put it in and it helps to block that allergic reaction from taking place; it dampens down the twitchiness of the muscles, the allergic cells, and so it calms the whole process down and it shrinks down all that inflammatory swelling.

Norman Swan: And safe? Because there have been some worrying findings in asthma. People taking them for long periods of time, of cataracts and so on.

Connie Katelaris: Sure, but in the nose we use much, much lower doses than you use in the respiratory tract, and the absorption from the nose is different to the huge surface area you have in the long, so we know that intra-nasal steroids are extremely safe.

Norman Swan: Another of the preventers that are used in asthma is, the trade name is Intal, but cromoglycate, which stabilises just these mass cells you're talking about. Now are there preparations of that that can be used in hay fever, particularly in the eyes?

Connie Katelaris: In the nose there has been for many years called Rynacrom and the one for the eyes is called Opticrom.

Norman Swan: That's the trade name?

Connie Katelaris: The trade names of this sodium cromoglycate which is the chemical name of the chemical you're talking about. It is an interesting molecule and for years we have called it a mast cell stabiliser, but in fact it probably isn't, and we know from trials done with newer agents compared with it, that it probably isn't quite as effective as we would all like it to be, as a preventing agent.

Norman Swan: So are there new things around that can help?

Connie Katelaris: Yes, and I suppose that's the exciting news of the last year or two, is that particularly for the ocular allergy, for the allergic conjunctivitis, we now have two groups of medications that are far more effective than anything we've had. The first are the preventers, which are non-steroid, and that's really important because steroid drops in the eye on a prolonged basis, cause a lot of problems like glaucoma and cataracts. So these are non-steroid preventing agents.

One group, the chemical name is nedocromil, not available here yet, but probably will come, and another group called lodoxamide and these are drops that you would use on a regular basis during your season of maximum symptoms, to lessen the allergic inflammation. And the second advance has been the development of targeted specific very, very potent antihistamines, which you put in directly into the eye. So these work basically on contact, immediately, rather than waiting for absorption, and they just go to the eye and they're very, very effective and we have one of these available in Australia now and there will be others coming.

Norman Swan: Isn't there a vicious circle here, that if you take the oral antihistamine it can dry up the eye and therefore make the conjunctivitis worse?

Connie Katelaris: Yes, and that's really important management point for people that do need to take oral antihistamines all the time. You do get lessening of the tear film and that can add to the discomfort in the eye. So people like this should be lubricating there eyes with one of the many artificial tear preparations they can buy over the counter.

Norman Swan: Is there any effective prevention? I mean given that the pollen gets everywhere, is there any way of effectively preventing the attacks?

Connie Katelaris: Well, you can always stay inside with the air conditioning on and the windows and doors shut. But that's fairly uncomfortable here in Australia. There are basic things people can do to start with. For instance, a simple pair of wrap-around sunglasses and a hat will really exclude the majority of pollen grains actually landing in the conjunctival sac to start with.

Norman Swan: What, that really makes a difference?

Connie Katelaris: It makes a big difference. And then when you've been outdoors and you come in, if you wash the eye out or lubricate it with the artificial tears or some sterile normal saline, you're actually removing the pollen grains that are there stimulating the reaction, and you're diluting or weakening the mediators, the allergic mediators that are in the tears. So you can just bring about a lessening of the attack by those simple, non-drug means.